hey, how you going? I went through the same process when i wanted to transfer degrees. Basically there are two ways you can go about switching degrees; the first is to apply through the Guaranteed Internal course transfer scheme. You have to have an ABOVE credit average, which means a GPA above 5 in order to get guaranteed entry. I copied and pasted the link on it for you
http://www.uws.edu.au/studyoptions/australian/undergraduate/transfer
I got the form from the student centre but i think u can also get it online from the forms page.
The other option is through UAC, where you apply as you did in order to get entry into your original degree, the only difference is you can now list additional qualifications, such as what you've already completed in your degree, tafe courses above Cert 3, work experience thats at least a year long, full time and payed and of course, Your UAI/HSC results. I applied using the form inside the UAC Guide i bought for around 15 bucks, but I'm pretty sure you can apply through their website,
www.uac.edu.au
When i was looking to transfer I applied through both cos I wasnt sure if i'd get an above credit average, so I had the UAC application to fall back on
Hope this helps, take it easy